ELLSWORTH, Maine — A man with a Veazie address was sentenced Monday to serve nine months in jail after pleading guilty to a single charge of gross sexual assault against a girl who was 13.

Charles F. Piatt, 28, was arrested on Nov. 1 after he admitted to having sex with the girl on Aug. 17, 2013, at a camp in Bucksport. According to a court document, Piatt told police he did not know the girl’s age, though the document also states that the victim and her mother both told police that they did alert Piatt to the girl’s age.

Though the girl was too young to consent legally to having sex with Piatt, the incident occurred without any compulsion, Piatt’s defense attorney, Jeff Toothaker of Ellsworth, told the judge on Monday in Hancock County Superior Court.

Toothaker told Justice Ann Murray that his client has some cognitive issues as a result of a car accident he was in when he was younger. Murray asked Piatt several times if he understood what was being discussed during the court proceeding, and each time he said, “Yes.”

Toothaker told the judge that his client thought the girl was older than 13 at the time of the incident but that Piatt understands that his impression at the time is irrelevant to the case.

Piatt declined to comment about his case when Murray gave him the chance to do so.

According to a court document, the victim’s mother reported the assault to Bucksport police on Oct. 11, after she heard about the incident from one of her daughter’s teachers.

Piatt and the victim met at the Bangor State Fair this year, the document stated. The two reportedly had conversations over the phone, which led to meetings and eventually the encounter in Bucksport where the assault took place.

The girl also told police that Piatt had given her alcohol.

Piatt was sentenced to four years with all but nine months suspended. He also was ordered to serve four years probation upon his release. As part of his probation, Piatt will not be allowed to possess or use alcohol or drugs, will have to undergo counseling, and will not be able to have unsupervised contact with girls under the age of 16 years old.

Piatt’s jail sentence was stayed until 9 a.m. Monday, Jan. 20, at which point he will have to turn himself in at the Hancock County Jail in Ellsworth.